A standard automatic pistol has a frame provided with a firing mechanism and carrying a slide comprising the barrel and breech block slidable on the frame. A recoil spring is braced between the frame and slide and the breech block is provided with a firing pin operable by a firing-pin spring or a hammer loaded by a hammer spring. The firing mechanism has an abutment guided generally parallel to and extending into the path of the firing pin or the hammer. This abutment is connected via a link with the trigger so that on actuation of same it is movable in a direction loading the firing pin or hammer.
Such pistols are relatively complicated to use. To chamber a cartridge it is necessary to pull back and then push forward the slide. Similarly when the cartridge clip is empty, the slide must be pulled back, a new clip inserted, then the slide released and moved forward to chamber the cartridge. All these actions must be carried out against heavy spring forces and in only one sequence, so that such a pistol can only be entrusted to experienced hands.
The shooter cannot often tell whether the pistol is on or off safety, especially after a pause in shooting. Thus it is possible for a shot to be attempted while the safety is on, or for a shot to be loosed inadvertently by someone thinking it is on when it is not.
Trigger-type automatics have a trigger that is cocked by the slide when a cartridge is chambered. In order to carry the loaded pistol with safety, the hammer must be uncocked. Subsequent shooting necessitates manually cocking the hammer by means of the trigger. This procedure requires that quite some force be exerted, necessitating a long trigger stroke without any noticeable critical point. The pistol is off safety after the shot, and subsequent shots only require limited force on and a limited stroke of the trigger, so that the danger of an unintentional shot is great. For safety against jarring and dropping, a particular latch for the firing pin is provided that is released on operation of the trigger before the hammer strikes the firing pin.
In addition, pistols are known with a separate safety lever which is actuated by the three fingers surrounding the pistol grip. It is, however, difficult to move these three fingers independently of the trigger finger so that mistakes in handling happen. In addition, with such a pistol whenever it is solidly gripped it is off safety, so that unintentional shots can be fired.
The known pistols have in common that the firing mechanism holds the firing element, that is, the firing pin or the hammer, in its cocked position and in this position the pistol is off safety and cocked so it is sensitive to jarring or dropping.
Another problem with the known automatic pistols is that removal of the barrel for servicing of the gun is fairly difficult, necessitating tools. In view of the need to maintain such complicated mechanisms carefully, such difficulty is extremely disadvantageous.
Yet another disadvantage of the known automatic pistols is that after the last shot in a clip the slide returns forward on the empty chamber. To chamber a new cartridge it is necessary to pull back the slide, insert the new clip, then advance the slide. In a situation where a pistol is used, such extra handling is very disadvantageous.